This invention relates to a method for directing and controlling the operation of an injection molding machine having sensors which provide actual values during machine operation, the machine having actuators forming and executing control commands received from the sensors.
Generally the directing and controlling of an injection molding machine is carried out in such a manner that from a central position all data from the sensors are processed according to a program, the control commands and controller output being established and passed on to the servo components. This, however, requires a considerable investment in hardware and software.
In other areas of technology, such as in telecommunications, it is known to execute control commands according to the multiplex process.
In data processing it is also known to transmit data according to the multiplex process.
Moreover, a publication entitled "Goals and Applications of Field Bus Systems", T. Pfeifer, et al., Vol. 29, Issue 12/1987, pp. 549-557, discloses the serial transmission of data by means of the so-called "field bus" systems.
It is also known to provide such field bus systems for motor vehicle control devices, as set forth in a publication entitled, "Bus System for Vehicle Control Devices", W. Botzenhardt, et al., VDI Report No. 612, 1986, pp. 459-470.
For injection molding machines the direction and control requires a profusion of data to be processed which, with serial processing, often involves insurmountable time problems.
For this reason it is generally not possible to utilize the known serial transmission systems
The processing of the data on parallel line systems, however, is uneconomical because of the software and hardware expenses.